ChemInform Abstract: RAMAN SPECTRA OF ICES II AND IX ABOVE 35 K AT ATMOSPHERIC PRESSURE: TRANSLATIONAL AND ROTATIONAL VIBRATIONS

Abstract

The Raman scattering by the translational and rotational vibrations of normal and deuterated ice II and ice IX at atmospheric pressure and 35–100 K is reported. The infrared absorption by deuterated ice II and ice IX at atmospheric pressure and 4.3 K is also reported. Imperfect, but useful, polarized Raman spectra of single crystals of ice II have indicated the symmetries of the vibrations. The translational vibrations have been reproduced remarkably well by normal coordinate and intensity calculations based on very simple force fields and models of the dipole moment and polarizability changes. No features could be assigned to longitudinal optic modes. Attempts to calculate the rotational and translational vibrations from the one force field were made for five force fields. No force field reproduced the observed separation of translational and rotational displacements in the normal vibrations for the actual structure. This experimental fact, that the vibrations are translational or rotational but not mixed, will provide a severe test for potential functions for the interaction between water molecules. A correction is given to the sample temperature cited in a previous publication about the OH and OD stretching vibrations of these ices [J. E. Bertie and B. F. Francis, J. Chem. Phys. 72, 2213 (1980)].